3 Storm Surge Character- 

 istics and Effects 



Reconnaissance of the affected area of the Outer Banks for evidence of 

 storm surge inundation began on 1 September 1993. Field teams from the 

 U.S. Geological Survey (USGS) office in Raleigh, NC, moved into the affected 

 area to identify high water marks. The USGS effort was performed under a 

 tasking from the Federal Emergency Management Agency (FEMA), with fund- 

 ing jointly provided by FEMA, the U.S. Army Corps of Engineers, and 

 National Weather Service. 



The USGS field teams identified 108 high-water marks on the Outer Banks 

 between the communities of Avon and Hatteras (see Figure 7 for locations of 

 communities). Of the 108 marks initially identified, 62 were selected as being 

 of sufficient quality to adequately represent the elevation and extent of flood- 

 ing. Each of the 62 selected marks was leveled using a total stations instru- 

 ment referenced to a local benchmark network. Data for each of the marks 

 were tabulated to show location referenced to latitude and longitude, type and 

 quality of mark, and the water-level and ground surface elevations. Marks 

 acquired inside structures are tabulated to the nearest hundredth foot, while 

 outside marks and ground elevations are tabulated to the nearest tenth. These 

 data are presented in Table 1; marks recovered inside structures are denoted as 

 "I," and marks recovered outside are denoted as "O." 



The northern extent of flooding along the Outer Banks barrier island occur- 

 red about 1 mile north of the Little Kinnakeet Coast Guard Station. To the 

 north of Little Kinnakeet, the elevation of coastal Highway 12 increases, form- 

 ing a barrier which confined the inundation to the narrow strip of land between 

 the shore and highway. 



To the south of Little Kinnakeet, the entire community of Avon was inun- 

 dated except for isolated elevated areas. South of Avon, Highway 12 was 

 inundated by water from the Pamlico Sound side of the barrier island, which 

 was prevented from flowing into the Atlantic Ocean by the beach dunes at 

 elevations higher than the highway. High-water marks acquired along this 

 stretch of Highway 12 were between 7 and 9 ft above National Geodetic Verti- 

 cal Datum (NGVD). Water levels increased in elevation as one approached 



Chapter 3 Storm Surge Characteristics and Effects 



